1. Field of the Invention
The present invention relates to a curved surface screen-printing apparatus for screen-printing a bent object.
2. Description of the Related Art
Screen-printing techniques for screen-printing cylindrical objects and bent objects have been known. Such conventional techniques print a pattern on a curved surface of a to-be-printed object by synchronously rotating the object. The to-be-printed object is limited to a radius of curvature of 0.3 to 0.4 m or so.
In recent years, there have been demands for screen-printing a to-be-printed object having a radius of curvature of 0.5 m or more. The radii of curvature of some to-be-printed objects reach 50 m. It is, however, extremely difficult to incorporate a device for rotating a to-be-printed object having a large radius of curvature into an existing printer. Thus, it is almost impossible to directly print a such a to-be-printed object.
Hitherto, to print such a cylindrical or bent object, a method has been adopted of first printing a planar object and then bending the printed object. Alternatively, a transfer printing method for transfer printing has been employed. The former method, however, has a drawback in that a printed surface of a to-be-printed object may be damaged because the object is bent after being printed. Further, the latter method has a drawback in that a misregister may occur when printing a large object. Thus, both of these methods are inferior both in finish and in the required time and effort to a method of directly printing a to-be-printed object.